Smart Grid: The Future of the Electric Energy System

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Smart Grid: The Future of the Electric Energy System

Mrs. Mubina Jamadar Mrs. Sharmin Sardar

Electrical Engineering Electrical Engineering

M.H. Saboo Siddik Polytechnic M. H. Saboo Siddik Polytechnic

Abstract:- The grid," refers to the electric grid, a network of transmission lines, substations, transformers and more that deliver electricity from the power plant to your home or business. The digital technology that allows for two-way communication between the utility and its customers, and the sensing along the transmission lines is what makes the grid smart. Like the Internet, the Smart Grid will consist of controls, computers, automation, and new technologies and equipment working together, but in this case, these technologies will work with the electrical grid to respond digitally to our quickly changing electric demand. The Smart Grid represents an unprecedented opportunity to move the energy industry into a new era of reliability, availability, and efficiency that will contribute to our economic and environmental health.

The benefits associated with the Smart Grid include:

  • More efficient transmission of electricity.

  • Quicker restoration of electricity after power disturbances.

  • Reduced operations and management costs for utilities, and ultimately lower power costs for consumers.

  • Reduced peak demand, which will also help lower electricity rates.

  • Increased integration of large-scale renewable energy systems.

  • Better integration of customer-owner power generation systems, including renewable energy systems.

  • Improved security.

A smarter grid will add resiliency to our electric power System and make it better prepared to address emergencies such as severe storms, earthquakes, large solar flares. Because of its two-way interactive capacity, the Smart Gridwill allow for automatic rerouting when equipment fails or outages occur. When a power outage occurs, Smart Grid technologies will detect and isolate the outages, containing them before they become large-scale blackouts. The new technologies will also help ensure that electricity recovery resumes quickly and strategically after an emergency routing electricity to emergency services first, for example. In addition, the Smart Grid will take greater advantage of customer-owned power generators to produce power when it is not available from utilities. By combining these "distributed generation" resources, a community could keep its health center, police department, traffic lights, phone System, and grocery store operating during emergencies. In addition, the Smart Grid is a way to address an aging energy infrastructure that needs to be upgraded or replaced. Its a way to address energy efficiency, to bring increased awareness to consumers about the connection between electricity use and the environment. And its a way to bring increased national security to our energy System.

  1. INTRODUCTION

Three dominant factors are impacting the future electric systems of the world; government policies, efficiency

needs of the consumer, and the introduction of new intelligent computer and hardware technologies. In addition, environmental concerns have created governmental policies around the world, which are driving the entire energy system to efficiency, conservation, and renewable sources of electricity. These factors are the main drivers that are expanding the use of all sorts of new renewable energy and storage technologies on the one hand and new energy efficiency and conservation techniques on the other. Consumers are becoming more proactive and are being empowered to engage in the energy consumption decisions affecting their day-to- day lives. At the same time, they are expanding their energy needs. For example, consumer participation will ultimately include extensive use of electric vehicles (both cars and trucks), remote control of in-home appliances to promote energy conservation, ownership of distributed generation from ever more renewable energy sources, and management of electricity storage to locally match supply to demand. The availability of new technologies such as more abundant and aware SCADA sensors, secure 2-way communications, integrated data management, and intelligent, autonomous controllers has opened up opportunities that did not exist even a decade ago

The electric energy system of the future needs to address all these needs and concerns by using advanced technologies to create a smarter, more efficient and sustainable grid. Many different definitions have been proposed for the Smart Grid, in most cases the users have chosen particularly focused definitions related to their specific applications and local needs. Below, we define the Smart Grid in its broadest global terms. We begin with a description of the makeup of the present conventional electric energy system, and we then identify the areas that must change in order to provide the intelligence and control necessary to convert to the safe, secure, and efficient Smart Grid of the future.

THE CONVENTIONAL ELECTRIC ENERGYSYSTEM

A general description of todays conventional electric delivery system is represented in figure 1. Traditionally the system is broken into mostly isolated components: generation, transmission, substation, distribution, and the consumer. Key characteristics of this conventional system that will be most strongly impacted by the changes required to implement the Smart Grid are the following attributes: centralized sources of power generation,

uni-directional flow of energy; from the source to the customers,

Passive participation by the customers; consumer knowledge of electrical energy usage is limited to amonthly bill received, after the fact, at the end of the month,

Real-time monitoring and control is mainly limited to generation and transmission, and only at some utilities, does it extend to the distribution system,

The system is not flexible so that it is difficult to either inject electricity from alternative sources at any point along the grid, or to efficiently and sustainably managenew services desired by the users of electricity.

Figure 1. Conventional Electric Grid

These conventional attributes have adequately served the needs of electric utilities and their customers in the past. However, the new needs of more energy knowledgeable, computer savvy, and environmentally conscious consumers, combined with regulatory changes that promote sustainability and energy independence from foreign sources, availability of more intelligent technologies, and ever greater demands for enough energy to drive the global economy, require an electric energy system of the future that is fundamentally different in all 5 areas listed above.

THE FUTURE SMART ELECTRICENERGY SYSTEM

A general schematic of the future electric energy system, or Smart Grid, is presented in figure 2. The key requirements of this system will address the following transformational functionalities:

Allow for the integration of renewable energy resources to address global climate change,

Allow for active customer participation to enable far better energy conservation,

Allow for cyber-secure communications systems to address system safety,

Allow for better utilization of existing assets to address long term sustainability,

Allow for optimized energy flow to reduce losses and lower the cost of energy,

Allow for the management of distributed generation and energy storage to eliminate or defer system expansion to reduce he overall cost of energy,

Allow for the integration of communication and control across the energy system to promote interoperability and open systems and to increase safety and operational flexibility.

Figure 2. The Smart Grid

It should be noted that the Smart Grid, as characterized above, does not replace the existing electric system but rather builds on the available infrastructure to increase the utilization of existing assets and to empower the implementation of the new functionality. For example, centralized sources of generation will still play a major role in the Smart Grid, and large-scale wind and solar generation, wherever cost justified, will become major parts of the generation mix. Availability of a 2-way, cyber- secure, end-to-end communications system will provide consumers with the knowledge of their energy usage necessary to allow them to locally and/or remotely control their smart appliances and temperature settings. Monitoring and control of the electric system components will provide the utility with the real time status of the system. The use of this real time data, combined with integrated system modeling and powerful new diagnostic tools and techniques, will provide the detection of incipient failures in order to drive preventive maintenance and dynamic work management systems. Automatic reconfiguration of the system, powered by sophisticated, adaptive and autonomous optimization controllers will maintain the flow of energy without interruption when equipment failures do happen. Distributed generation and storage resources and remotely controlled equipment will also play an important role in the management of the Smart Grid energy system not only to address contingency needs but also to optimize power flow, eliminate load pockets, and minimize system losses. It should be noted that building the Smart Grid, as envisioned here, will be very costly and will require a sustained implementation process that evolves over decades.

DEFINITION OF THE SMARTGRID

The Smart Grid is defined as an electric system that uses information, two-way, cyber-secure communication technologies, and computational intelligence in an integrated fashion across electricity generation, transmission, substations, distribution and consumption to achieve.

Secure communications (two-way) covering the system from end-to-end,

All main components are sensed and variances detected: cables, joints, terminations, transformers, consumer usage, power quality, etc. will be monitored in real time. a system that is clean, safe, secure, reliable, resilient, efficient and sustainable. This definition covers the entire spectrum of the energy system from the generation to the end points of consumption of the electricity. The reader will note that many definitions proposed by other users are subsets of this system-of- systems definition; as for example, if defined as smart metering, it addresses the consumption and to some extent the distribution part of this definition but not the full spectrum of integration required to implement the Smart Grid.

Achieving a smart grid will be a gradual and evolutionary process that will take many decades to befully realized. To qualify as a Smart Grid, it is neither necessary nor feasible to incorporate all features at one time, but rather incorporation of each new feature can be carried out independently. Each will require cost justification and reasonable pay back on investments. The above characteristics will provide massive amounts of incoming data that must be converted into situational awareness of the state of the grid. Controller technologies will then have to automate data and energy management so that information is streamlined, problems are diagnosed instantly, corrective actions are identified and executed dynamically in the field, and feedback loops provide metrics that verify that the work done is producing the desired effects. Such Smart Grid controllers will have the following characteristics:

Self healing: automatic repair or removal of potentially faulty equipment from service before it fails, and reconfiguration of the system to reroute supplies of energy to sustain power to all customers,

Flexible: the rapid and safe interconnection of distributed generation and energy storage at any point on the system at anytime,

Predictive: use of machine and reinforcement learning, weather impact projections, and stochastic analysis to provide predictions of the next most likely events sothat appropriate actions are taken to reconfigure thesystem before next worst events can happen, Interactive:

appropriate information is providedtransparently regarding the status

of the system not onlyto the operators but also to the customers to allow allkey participants in the energy system to play an activerole in optimal management of contingencies.

Optimized: knowing the status of every major component in real or near real time and having control equipment to provide optional routing paths provides the capability for autonomous optimization of the flow of electricity throughout the system.

Secure: considering the two-way communication capability of the Smart Grid covering the end-to-end system, the need for physical- as well as cyber-security of all critical assets is essential.

Figure 3. New equipment of the Smart Grid

MAJOR NEW COMPONENTS OF THE

SMARTGRID

As indicated by the above characteristics, the Smart Grid involves installation of much new, intelligent equipment at critical generation, transmission, distribution, and consumption points. For this equipment to become an effective part of the operations of an integrated Smart Grid, fundamental control technologies for communications, data

management, diagnostic analysis, and work management are required. The Smart Grid must operate as an integrated machine: a system-of- systems. As shown in figure 3, the Smart Grid will change the conventional concept of energy management and operations since traditional blind demand will evolve to become controlled visible demand. In some cases, demand will be convertable into supply.

Customer Demand, Demand Response and Curtailable Loads

Many people, especially in the public sector, consider the Smart Grid to be nothing if not Advanced Metering Infrastructure (AMI), including Automatic Meter Reading (AMR). More advanced features of an integrated AMI includes a Distribution Management System with full control, monitoring and Geographic Information System (GIS) interfaces. In addition, AMI Smart Grid systems provide consumption control at the customer site, distributed load management, and 2- way communications (c.f.,Mahmood, Aamir, and Anis, 2008).

EV,Charging Stations and Microgrids

Electric Vehicles and Plug-in Hybrid Electric Vehicles (grouped as EVs here) present unique problems for the electric grid because they are mobile sinks for power in the day and fixed sinks at night. The perception for mostneeded intelligent interaction via the Smart Grid comes during the day in large urban areas, when large populations of EV vehicles are predicted to plug into the grid for recharging upon arrival at work, just as the electricity consumption of large urban cities is ramping up towards peak. A further homeland security need is that each EV must receive at least a 25% recharge so all vehicles can make it out of the city limits in case of an emergency. Thus, load transfer to storage facilities linked to EV charging stations is being considered in addition to grid charging. In addition, so called Green Garages are beginning to appear, that certify that the power used to charge the EV comes from renewable energy sources, even as that fact is hard to verify.However, EVs could represent a significant mobile

source of emergency power in case of crisis situations such as blackouts.

Micro Grids are small scale grids within the electric grid where distributed generation sources such as

PV and wind are linked to distributed storage, and at least in concept, E charging stations. They provide

local electric distribution for neighborhood, campus, manufacturing facility, etc

that can be independent of the grid itself. Micro Grids also include local load control, and often Heating Ventilation and Air Conditioning (HVAC) of large vertical buildings or groups of buildings. Micro Grids are designed to be able to stand alone from the electric grid (islanding) in times of crisis so that the power in the local area can be maintained via emergency generation. Micro Grids can also be used for significant curtailable load for utilities during peak load reliefperiods (c.f. M. Dicorato, et. al.,2009).

Actions between Micro Grids and the Smart Grid can then be coordinated to maintain optimal power flow, protection & switch coordination, while managing restoration plans and replacement options, all the while responding to financial and market variations.

Energy Storage

A critical addition to the Smart Grid will be from the addition of significant energy storage capability. Intermittent power sources like PV, Solar Thermal, and Wind require someplace to store the electricity to fill needs during cloudy and/or windless times. The Electricity Storage Organization tracks the cost of both large and small scale energy storage systems, from Lithium-Ion, Nickel- Cadmium and Lead-Acid batteries, through fly wheels and super- capacitors, to various large scale battery storage devices, and finally to large scale cavern storage of compressed air and hydroelectric that involves pumping water back upstream during nights.

These technologies are all technologically viable, if affordable: a barrier that has not yet been passed.

Until it is, large-scale deployment of alternative energy sources will be limited. Other electricity

storage devices that involve melting salt, heating vegetableoils,

freezing ice for HVAC chiller operations, and the use offuel cells have attained wider, though still limited, deployment

Distributed- and Co- Generation

The Smart Grid must be able to accommodate small- scale generation owned by customers such as combined heat and power co-generation facilities, as well as from the previously mentioned PV, EV and MicroGrid sources. Power management of distributed generation involving everything from Building Management Systems to solar generation depends on accurate weather forecasting, which adds to the uncertainties being optimized by smart grid control systems. New methods linking these erratic sources to storage are required to provide dispatchable loads (c.f., Jiang, 2006,and Chowdhury and Koval,2005).

Massive Solar Thermal and Wind Farm Generation

Solar Thermal power generation, in particular, has been very successful in linking mirrors to a storage medium, usually a salt that is melted or vegetable oil that is heated.

Both can be used to boil water for

many hours afterwards. This combination has allowed the design of every large Solar Thermal power plants. It should be theoretically possible to build such plants thatgenerate as much electricity as the other two largest alternative energy sources to burning hydrocarbons: nuclear and hydroelectric. Arizona has begun construction of the first 280 MW of an intended 4300 MW Solar Thermal plant south of Phoenix (Figure4).

Figure 4. An artists representation of the first 280 MW module of a Solar Thermal Power Plant complex southwest of Phoenix, Arizona, that will be selling power into the Western Interconnect and Southern California (imagecourtesy of Arizona State University).

Nanotechnologies and Power Generation and Storage of the Future

Above all, the Smart Grid must have the capacity to adapt to new technologies not yet invented or in long

term development such as fusion nuclear, or more likely, nanotechnology breakthroughs. Examples of future Nanotechnologies that might be important energy sources or storage media within the next 10 years (Smalley, 2007) include (Figure 5):

Photovoltaic materials that may drop cost by 100 fold or more

Photocatalysts that reduce CO2 emissions to methanol Nano-materials that directly convert light and water to produce hydrogen via thermo chemical catalysts that generate Hydrogen from water and that work efficiently at temperatures lower than 900C

Nano Fuel Cells that drop the cost by 10-100x and provide low temp starting capacity and are reversible Direct Hydrogen storage using lightweight Nano materials for pressure tanks and/or a new lightweight, easily reversible hydrogen chemisorptions system (called material X) Batteries, super capacitors, and flywheels improved by 10-100x for automotive and distributed

generation applications

High current quantum wires (QW) that might rewire the transmission grid and enable continental, and even worldwide electrical energy transport; and also to replace aluminum and copper wires essentially everywhere — particularly in the windings of electric motors and generators

Nano electronics to revolutionize computers, sensors and devices.

Nano Robotics with Artificial Intelligence to enable construction and maintenance of solar structures in space and on the moon; and to enable nuclear reactor maintenance and fuel reprocessing on Earth

Super-strong, lightweight materials to drop cost to launch solar arrays in to space

Thermochemical catalysts to generate H2 from waterthat work efficiently at temperatures lower than 900C.

Nanotech lighting to replace incandescent andfluorescent lights

Nano-Photovoltaics — new paints for the exterior of buildings that generate electricity

Figure 5. Plenty of room at the bottom, according to Richard Feynman, describing nanotechnology opportunities (c.f., Hey, J.G., Feynman and computation: exploring the limits of computers, Westview Press, 2002).

Source: Baker Institute Study No. 30, Energy and Nanotechnology, Strategy for the Future, Rice University, April, 2005, accessable at: http://www.rice.edu/energy/publications/energynanotechno logy.html.

Taking the most likely of these to first appear on the Smart Grid, Quantum wires (QW) have the electrical conductivity of copper at one-sixth the weight and it will be stronger than Kevlar. They can be spun into polypropylene-like rope and used for the transmission grid of the future.

ADAPTIVE STOCHASTICCONTROL

A key to the implementation of the Smart Grid is to create the intelligent management of the margin between the ever-expanding demand for electricity and its efficient, safe, secure, and sustainable supply at all points along the distribution path. Electricity is no longer entering the grid exclusively at massive power plants on the transmission beginnings of the

grid, but it will also be generated from distributed resources

at customer sites throughout the distribution grid, and even from energy storage at consumer sites and substations. As indicated in Figure 6, intelligent controllers must receive, digest, and interpret all manner of new data coming from SCADA sources and send commands to manage contingencies, optimize power flows, initiate preventive maintenance, control switching and load, minimize capital investment, deal with erratic solar and wind generation, and optimize distributed storage, all the while dealing with potential and real equipment failures as well as weather and pricevariations.

Figure 6. The Smart Grid must optimally interpret incoming data from many new sources (green) with newcontrols such as Contingency Analysis Programs (CAPin the upper right) and Capital Asset Prioritization Tools (CAPT in lower right).

This Smart Grid data and energy management system must be, by definition, adaptive and stochastic, meaning that it is prepared to respond to varying weather conditions, crew status, and equipment performance changes while optimizing supply to meet demand within economic constraints that simultaneously minimize costs for consumers, regulators and industry stockholders.

Some utilities now use complex, coputational command and control systems similar to those used in petrochemical and nuclear plant management, such as decision support and portfolio management tools, activity based accounting, and preventive maintenance programs. However, the computational systems utilized in these controller calculations are generally policy- and-rules-based decision systems. Risk and variance areconsidered using linear programming algorithms. These systems are very good at identifying the next worst condition that can happen to the electric grid at any given time, but not so good at determining actions to prevent the next most likely condition to occur on the electric grid.

Controlling the new complexities of the Smart Grid is a multi-stage, time-variable, stochastic optimization problem to the Operation Research engineer and operator. The Adaptive Stochastic Controller (ASC) for the Smart Grid requires the import of Approximate Dynamic Programming

(ADP) and Mixed-Integer, Nonlinear Programming solvers that are more familiar to the petrochemical and transportation industries.

Current business plans for utilities are also based on risk/reward optimization algorithms, although these are usually Net Present Value (NPV) computations used in a portfolio management context. The future Smart Grid will be too dynamic and too complex for such linear methodologies.

Load & Source Control:

The control of distributed energy storage for the real time Load and Source Control has been mostly limited to date to pumped hydro. However, recent demonstration projects are providing new opportunities to show the value of energy storage in the control of grid stabilization, operations support, power quality management, and load shifting applications. Candidatehigh value applications are: Instantaneous versus Ramp Rate Limited Generation Based Spinning Reserve as Bridge Power to Standby Generation in the Event of Loss of Generation or Transmission Cycling Power Supply and Load Arbitrage Regulation Control Support

Reserve Power for System Power Reliability, Securityand Quality

Utility Load Shifting for Supply Infrastructure Asset Optimization and Emergency Response

End-user Energy Management and

PowerQuality/Reliability Requirements Intermittent Renewable Power (e.g., Wind) Stabilityand Optimization

ADP Adaptive Stochastic Control for Load and Source management must exercise real options decisions in real time based on price and market condition informationfed to the controller. The real time options include: option value of arbitrage,

option value of peak shaving,

option value of greater network reliability,option value of environmental benefits Dynamic Treatment

ADP Adaptive Stochastic Control also provides Dynamic Treatment optimization for maintenance operations. Machine Learning and statistical models for failure that use causal inference, propensity and survivalanalysis developed for the medical industry have been shown effective to arrive at treatment actions to prevent electric grid failures (Rudin, et al, 2011). The dynamic treatment output of Adaptive Stochastic Control is a prioritization of work needed and control actions to be taken, either discretely or continuously, to keep grid devices such as distributed generation and storage, sectionalizing switches, and load pockets within optimal performance bounds.

Adaptive Stochastic Control in Transmission

The Adaptive Stochastic Control functions for the Smart Grid also include static and dynamic security assessment capabilities along with self-checking of relay settings on critical transmission facilities. With the deployment of phasor measurement units to monitor grid performance

across heavily loaded regional transmission interconnections, there will be advances in state estimators that are capable of real- time simulations for large networks that will need to be incorporated into the overall management of the Smart Grid. For example, mobilizing grid capacity reserves through active management to avoid overloads will enable operators to relieve bottlenecks and redeploy necessary generation and transmission assets from both the transmission and distribution grids to eliminate congestion points and load pockets in the integrated transmission and distribution grids.

CHALLENGES TO ACHIEVINGACOMPREHENSIVE SMART GRID

A primary objective of the Smart Grid is to improve our capacity to use more, but cheaper, electricity to power the improvements in the standard-of-living of all people on Planet Earth. However, the transition must be cost effective, or we will never get there from here. The tracking of key performance metrics that continuously and automatically score improvements generated by the Smart Grid will be required if the effort is sustainable over the 20 to30 to a comprehensive Smart Grid in any country. Documenting these improvements requires the establishment of an initial baseline for all major components of the existing grid, and then continuous measurement of the impact of new construction and implementation against that baseline. A benefit from this documentation will be that Adaptive Stochastic Controllers of the Smart Grid will have been validated to redirect load around congestion, manage peak demand, weather and equipment problems that will eliminate the need for expensive new power plants and substations. Internationally, computers operating these Adaptive Stochastic Controllers managing every level of the new Smart Grid could eventually save the need to build Terra- watts of new generation worldwide.

It is expected that over time the Smart Grid will improve the capacity factor of the electric system through more optimal supply and demand management. It allows for the re-use of existing hardware infrastructure in a more efficient manner by adding modern controller intelligence to the existing system. Understanding the risks and consumer impact of using the available resources optimally should allow Smart Grid utilities to lower peak demand and reduce Capital and O&M costs by mitigating emergencies of all kinds during peak load periods. It is our joint task as an industry to maintain the tracking metrics worldwide to document that these predicted benefits are actually realized by the Smart Grid implementation we are all beginning.

Bestpractices should be shared easily and efficiently.

Challenges to the future success of the smart grid come from many fronts, such as consumer buy-in: consumers have to see real savings and efficiency improvements; better regulation: governmental control must stay up to date technologically and in touch with consumers; cost

justification; Smart Grid components must be individually as well as systemically cost effective; education: utilities, service companies and universities must produce educated consumers as well as a new generation of electrical engineer savvy in computer sciences and systems engineering; and new inventions and technologies must be easily adopted and adapted years that will be required for a full conversion

REFERENCES

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  2. Garrity, T., Innovation and Trends forFuture Electric PowerSystems, IEEE Power and Energy, 38-45, March-April,2008.

  3. Katz, J., Educating the Smart Grid, IEEE Energy 2030,2008.

  4. Tsoukalas, L., and R. Gao, From Smart Grids to an Energy Internet Assumptions, Architectures and Requirements, IEEE DRPT Conference, April,2008..

  5. Smalley, R., Our Energy Challenge, thttp://video.google.com/videoplay?docid=-4626573768558163231#

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